Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
su sach » so sach, vu sach
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
hai cau » hai chau, hai chu, hai hau
hieu va » lieu va, hieu qua
cao hoi » cau hoi, co hoi, cao hoc
ly nang » ky nang, ly hang, ly vang
y nang » ky nang, v nang, may nang
va nam » van nam, ha nam, va nay

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((y nang) or (ly nang)) cao hoi. hieu va nam thuoc ((va hanh) OR (va danh)) hai cau thi~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ly nang)) cao hoi. hieu va nam thuoc ((va hanh) OR (va danh)) hai cau thi.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) or (ly nang)) cao hoi. hieu va nam thuoc ((va hanh) OR (va danh)) hai cau thi".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (ly nang)) cao hoi. hieu va nam thuoc ((va hanh) OR (va danh)) hai cau thi*.